1. Field of the Invention
The present invention relates to an ammonia absorption chiller heater with air-cooling means and a modification method therefor.
2. Description of the Related Art
An absorption chiller heater in Japanese Patent Laid-Open Publication No.Hei 11-223432 is publicly known which uses ammonia as a refrigerant and water as an absorbent and is equipped with air-cooling means.
Description will here be given of the known art mentioned above.
In a generator, ammonia aqueous solution is heated to generate ammonia vapor.
This heating is performed by using a gas burner.
The ammonia aqueous solution having ammonia vapor generated therefrom makes dilute ammonia water.
The ammonia vapor generated in the generator is introduced to a condenser. The vapor is circulated through a heat exchanger while air-cooled by a cooling fan, thereby being condensed into liquid ammonia.
The condensed liquid ammonia is let through an expansion valve for pressure reduction, and fed to an evaporator.
In the evaporator, the liquid ammonia evaporates into ammonia vapor, which consumes heat of evaporation to cool brine. This cooled brain is circulated through cool/heat loads to offer a refrigeration effect or cooling effect.
Meanwhile, the dilute ammonia water obtained through the generation of ammonia vapor in the generator described above is introduced through a pressure-reducing valve and sprayed into the upper part of an absorber. At the same time, the ammonia vapor having evaporated in the evaporator is also introduced to the absorber mentioned above.
In this absorber, the dilute ammonia water absorbs the ammonia vapor to make dense ammonia aqueous solution, which is sent back to the aforementioned generator by a solution pump. The ammonia aqueous solution is then reheated by the gas burner to generate ammonia vapor therefrom, making diluted ammonia water again.
Subsequently, these processes are repeated to carry out the refrigeration cycle.
As has been described above, the known art uses a gas burner to heat ammonia aqueous solution in the generator.
The use of a gas burner is advantageous for compact configuration of the entire absorption chiller heater. However, gaseous fuel is high in cost per calorie and therefore uneconomical as compared to liquid fuel.
Under such circumstances, conversion of the gas burner into a fuel oil burner is desired by users.
Liquid fuel is, however, greater in specific gravity and viscosity as compared to gaseous fuel. Therefore, liquid fuel needs to be atomized by spraying so as to mix with air, which elongates the flame.
Long flames from a burner give rise to a problem as follows:
The generator of an absorption chiller heater typically comprises heat transfer fins on its peripheries. Here, high-temperature gas produced by combustion flows in contact with the heat transfer fins to heat the entire generator.
If a flame reaches the heat transfer fins, the fins might locally be overheated until burned out, or combustion-produced solids might adhere to the fins to hamper the heat transfer. Thus, the burner must be placed so that the extremity of the flame cannot come to touch the heat transfer fins.
Accordingly, the longer the flame is, the greater the distance between the burner and the generator must be to establish a flame channel greater in length. This enlarges the entire shape and size of the absorption chiller beater. On this account, a wider floor space is required for installation.